All of our Kontakt and Reaktor-based products require activation through Native Instruments. When you first add the library, you will be prompted to enter your serial number in Native Access. If you have already activated the product on a different system, make sure you are signed in with the NI account you used to originally activate the product.
If activation fails in the Native Access application, it should provide an error code explaining the issue. Please relay that code to support(at)heavyocity.com so we can quickly resolve the issue.